Such a clamp is known from DE-88 14 208 U and EP-0 369 197 B1 and has given satisfactory results particularly with respect to the simplicity of operation, accompanied by effective generation of the clamping force required. In those references the actuating element is in the form of an eccentric with an actuating lever, whereby at the same time as being rotatable the axis of rotation of the eccentric is also displaceable at right angles to the lining skin. When this eccentric is turned, the displacement of its rotary and swivel bearing simultaneously causes a corresponding displacement of the two adjusting arms engaged by the eccentric in the area of this rotary or swivel bearing. The swivel movement of the adjusting arms away from the lining skin simultaneously swivels the clamping jaws towards the edge sections to be connected together. This represents a clamp which is very simple to operate.
However, if operated improperly, the edge sections to be connected may be subjected to excessive clamping force. This may be the case if two edge webs to be connected have a spacer placed between them to make up for dimensional discrepancies and the user nevertheless turns the eccentric the whole way. Furthermore, one cannot tell from the clamp, which can be used turned 180.degree. about a horizontal axis, in which swivel position the actuating lever is in the closed position.
DE-42 36 070 A1 discloses a clamp for connecting the sections at the edges of form panels, which due to its overall design is more suited for connecting sections having more or less flat webs. The clamping jaws do not have any angled adjusting arms. Rather, the point for applying an adjusting element in the form of a wedge is located in extension of the clamping jaws themselves. A clamp for holding together edge sections of hollow form would therefore have a very large overall dimension, the clamp having to be applied on the one hand to two widely spaced application points of both clamping jaws and on the other hand inside the housing carrying the clamping jaws. If the clamp is configured for connecting hollow webs, this housing in particular would have to be of relatively great length, necessitating that the wedge would also have to be correspondingly long. This one wedge may then no longer be sure to swivel both clamping jaws with sufficiently great force.
German Utility Model No. 80 09 045 discloses a device of a different character for connecting form panels disposed in side-by-side relation, namely a bolt which traverses and urges together the webs at the edges of two form panels through a pulling force applied to the bolt. This pulling force may be applied either with the aid of an eccentric mounted on the bolt through a transverse pin or with the aid of a wedge traversing a slot in the bolt or with the aid of a thread on the bolt. Since the device is not a clamp, there are no swivelling clamping jaws urging together the abutting edge sections.